# US 8,772,866 B2 · Semiconductor device and method for fabricating the same

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- Number: US 8,772,866 B2
- Document ID: US8772866B2
- Status: Granted
- Kind: B2
- Application number: 12/650,436
- Filed: 2009-12-30
- Published: 2011-02-03
- Granted: 2014-07-08
- Earliest claimed: 2009-07-28
- Assignees: Hynix Semiconductor Inc.
- Applicants: Sung Pyo Hong
- Inventors: Sung Pyo Hong
- Web page: https://patentgrep.com/patent/US8772866B2

## CPC

- H10W 20/069: {by forming self-aligned vias or self-aligned contact plugs}
- H10D 64/027: {by etching at gate locations}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A semiconductor device comprises a buried gate formed by being buried under a surface of a semiconductor substrate, a dummy gate formed on the buried gate, and a landing plug formed on a junction region of the semiconductor substrate being adjacent to the dummy gate.

## Claims

### Claim 1

A semiconductor device, comprising:
a buried gate provided entirely within a recess of a semiconductor substrate;
a sealing nitride film formed over the buried gate and at least within the recess;
a capping oxide film formed over the sealing nitride film and at least within the recess;
a dummy gate formed over the capping oxide film; and
a landing plug formed over a junction region of the semiconductor substrate provided adjacent to the dummy gate.

### Claim 2 (depends on 1)

The semiconductor device according to claim 1, wherein the dummy gate includes a nitride film.

### Claim 3 (depends on 1)

The semiconductor device according to claim 1, wherein the buried gate includes:
a gate dielectric film formed over a surface of the recess; and
a gate conductive layer formed within the recess over the gate dielectric film,
wherein the dummy gate includes nitride.

### Claim 4 (depends on 3)

The semiconductor device according to claim 3, wherein the gate conductive layer includes TiN and W.

### Claim 5 (depends on 1)

The semiconductor device according to claim 1, further comprising an interlayer dielectric formed over a surface of the semiconductor substrate including the dummy gate, wherein the dummy gate has different etch characteristics than the interlayer dielectric.

### Claim 6 (depends on 1)

The semiconductor device according to claim 1, further comprising a bit line contact plug and a storage node contact plug formed over the landing plug.

### Claim 7

A manufacturing method of a semiconductor device, comprising:
forming first and second buried gates within first and second recesses of a semiconductor substrate, respectively, the first and second buried gates each being provided entirely within the first and second recesses, respectively;
forming first and second sealing nitride films over the first and second buried gates and at least within the first and second recesses, respectively;
forming first and second capping oxide films over the first and second sealing nitride films and at least within the first and second recesses, respectively;
forming first and second dummy gates over the first and second capping oxide films, respectively, the first and second dummy gates defining a landing plug contact area therebetween;
forming an interlayer dielectric over the first and second dummy gates and the landing plug contact area;
etching the interlayer dielectric using the first and second dummy gates as etch masks to form a landing plug contact hole that exposes a surface of the semiconductor substrate, the landing plug contact hole corresponding to the landing plug contact area defined by the first and second dummy gates; and
forming a landing plug within the landing plug contact hole, the landing plug contacting a junction region of the semiconductor substrate.

### Claim 8 (depends on 7)

The manufacturing method according to claim 7, further comprising:
removing the interlayer dielectric at least until the first and second dummy gates are exposed,
wherein the interlayer dielectric is etched to form the landing plug contact hole after the first and second dummy gates have been exposed.

### Claim 9 (depends on 7)

The manufacturing method according to claim 7, wherein the forming the first and second dummy gates include:
depositing a dummy gate material over the semiconductor substrate;
forming a photoresist pattern over the dummy gate material; and
etching the dummy gate material using the photoresist pattern as a mask.

### Claim 10 (depends on 7)

The manufacturing method according to claim 7, wherein the forming the first and second buried gates includes:
forming the recess in the semiconductor substrate;
forming a gate dielectric film over a surface of the recess; and
forming a gate conductive layer over the gate dielectric film and within the recess.

### Claim 11 (depends on 10)

The manufacturing method according to claim 10, wherein the gate conductive layer includes TiN and W, and the first and second dummy gates include nitride.

### Claim 12 (depends on 7)

The manufacturing method according to claim 7, wherein the interlayer dielectric and the first and second dummy gates have different etch characteristics.

### Claim 13 (depends on 7)

The manufacturing method according to claim 7, further comprising:
forming a mask pattern over the first and second dummy gates to define the landing plug contact hole,
wherein the landing plug contact hole is formed by etching the interlayer dielectric using the mask pattern and the first and second dummy gates as the etch mask.

### Claim 14

A manufacturing method of a semiconductor device, comprising:
forming a recess in a semiconductor substrate;
coating a gate oxide film over a surface of the recess;
providing a gate conductive layer within the recess to form a buried gate, the buried gate being provided entirely within the recess;
forming a sealing nitride film over a surface of the gate conductive layer and at least within the recess;
forming a capping oxide film over the sealing nitride film and at least within the recess;
depositing a dummy gate material over the semiconductor substrate;
etching the dummy gate material to form a dummy gate over the buried gate;
forming an interlayer dielectric over the semiconductor substrate including the dummy gate;
etching the interlayer dielectric using the dummy gate as an etch mask to form a landing plug contact hole exposing the surface of the semiconductor substrate; and
providing a landing plug material within the landing plug contact hole to form a landing plug adjacent to the dummy gate.

### Claim 15 (depends on 14)

The manufacturing method according to claim 14, further comprising forming a bit line contact plug and a storage node contact plug over the landing plug.

### Claim 16 (depends on 14)

The manufacturing method according to claim 14, wherein the dummy gate material includes nitride.

### Claim 17 (depends on 14)

The manufacturing method according to claim 14, wherein the gate conductive layer includes TiN and W.